Circular Segment Area Calculator

Calculate the area of a circular segment using radius and segment height, radius and central angle, chord length and height, or arc length and radius. Estimate chord length, arc length, sector area, triangle area, square feet, square meters, material coverage, waste, and cost.

Calculate Circular Segment Area

Circular Segment Area = Sector Area − Triangle Area. Minor Segment Area = ½r²(θ − sin θ), where θ is in radians.
Your result will appear here.

How the circular segment area calculator works

Radius and height mode:
The calculator uses the circle radius and segment height to estimate the central angle, chord length, arc length, and segment area.

Radius and angle mode:
The calculator uses the central angle to calculate sector area, triangle area, and segment area.

Chord and height mode:
The calculator estimates the radius from the measured chord length and segment height, then calculates the segment area.

Project estimate:
The calculator adds quantity, excluded area, waste, material units, edge cost, labor cost, and total estimated cost.

Why use a circular segment area calculator?

A circular segment area calculator helps estimate curved portions of circles used in arches, circular windows, landscaping curves, pool edges, concrete forms, round tanks, geometry problems, and custom curved designs.

It can help calculate segment area, chord length, arc length, sector area, triangle area, central angle, square feet, square meters, material quantity, waste, and estimated cost.

What your result means

Your result shows circular segment area, area with waste, chord length, arc length, central angle, sector area, triangle area, square yards, square meters, acres, material units, edge cost, labor cost, and estimated total cost.

Circular segment area formulas

Frequently asked questions

What is a circular segment?

A circular segment is the part of a circle between a chord and the curved arc above or below that chord.

How do I calculate circular segment area?

For a minor segment, use ½r²(θ − sin θ), where r is the radius and θ is the central angle in radians.

What is the difference between a sector and a segment?

A sector is the wedge-shaped area between two radii and an arc. A segment is the area between a chord and an arc.

Can I calculate segment area from chord length and height?

Yes. The calculator can estimate radius from chord length and segment height, then calculate the segment area.

Is this circular segment area calculator exact?

It is exact for clean geometric inputs, but real project estimates can vary by measurement accuracy, curved cuts, material waste, rounding, and installation method.